UN Secretary General Ban Ki-moon late Wednesday delivered his strongest condemnation yet of the fighting between Israel and Hamas, saying both sides made use of weapons in an irresponsible manner.

UN Secretary General Ban Ki-moon late Wednesday delivered his strongest condemnation yet of the fighting between Israel and Hamas, saying both sides made use of weapons in an irresponsible manner.

"The civilian population, the fabric of Gaza, the future of the peace process, stability in the region, and goodwill among people throughout the world: all are trapped between the irresponsibility displayed in the indiscriminate rocket attacks by Hamas militants and the disproportionality of the continuing Israeli military operation," Ban told an emergency meeting of the UN Security Council in New York.

"Let me be clear: I condemn unequivocally and in the strongest possible terms the ongoing rocket and mortar attacks by Hamas and other Palestinian militants," he said. "But I also condemn the excessive use of force by Israel. All parties must fully uphold international humanitarian law."

Ban deplored the fact that calls issued by the 15-nation council four days ago at the start of the Israeli airstrikes against Hamas for firing rockets and mortars into southern Israel went unheeded. He repeated his own demand for an "immediate ceasefire to be fully respected" by all parties.

"The parties must step back from the brink," he said. "All this violence must end."

The council convened on New Year's Eve to hear addresses by representatives of the Arab League, who conveyed its decision in Cairo on Wednesday to seek a UN demand that Israel and Hamas end the hostilities that had entered a fifth day.

The Arab League said it plans to submit a draft resolution early next week to demand a ceasefire and the reopening of crossings into Gaza so humanitarian and medical supplies can reach those most in need of assistance, particularly hospitals that have treating hundreds of people injured by the fighting. The draft would call also for dialogue between the two sides in order to end the conflict.

In his address to the council, Ban said the people of Gaza are living under heavy bombardment targeted at Hamas facilities, smuggling tunnels and Hamas infrastructure. The bombardment is also aimed at Palestinian government buildings, residential homes, mosques and businesses.

"Over 300 people lie dead, among them at least 60 women and children," Ban said. "Over 800 are wounded."

He said Hamas militants have now used longer-range missiles to hit major Israeli cities.

"Schools have closed and daily life in southern Israel is extremely difficult as Israelis live in constant fear of rockets which have hit homes and schools," he said. "It is the civilian populations that are bearing the brunt of this escalation, and there must be swift and decisive action by the international community to bring to an end their suffering."

Ban said some humanitarian supplies have been allowed by Israel to reach Gaza, with a total of 84 truckloads passing through the Kerem Shalom crossing on Wednesday. The UN has been able to open seven emergency distribution centres, manned by a small staff. But he said other crossings remained closed and a fuel shortage has led to the closure of Gaza power plant.

He called for the opening of the Nahal Oz and Karni crossings to allow more provisions of food and fuel into Gaza.

"There must be an immediate ceasefire that is fully respected by all parties," he said. "This must create new conditions on the ground that ensure at last that crossings into Gaza will be reopened; that rocket attacks and weapons smuggling will end; and that we will pursue political dialogue, and only political dialogue, to reunite Gaza with the West Bank; and that the root cause of this suffering, the absence of Israeli-Palestinian peace, is ended."